The invention relates to a method for jointly controlling asynchronous machines of a motor vehicle, and to a control device for controlling such a method.
Although the present invention and the underlying problem thereof are described with reference to an electric vehicle comprising two asynchronous machines (ASM), each of which drives one wheel of a shared vehicle axle, the invention can also be applied to any other motor vehicles comprising multiple asynchronous machines in different configurations at the wheels and/or the vehicle axles of the particular motor vehicle.
In many applications of electric drive technology, situations occur in which it is advantageous to install two or more electrical machines in a motor vehicle. In the field of electric or hybrid-electric vehicles, a multiplicity of different topologies for the configuration of the drive train are utilized, in which multiple asynchronous machines or the like can be arranged in different ways. For example, there are solutions for all-wheel drive electric vehicles, in which each axle is driven by an ASM which transfers a drive torque, via a differential, to the wheels of the motor vehicle located on the particular axle. Alternatively, there are configurations in which individual wheels are each driven by one associated ASM. In the case of an all-wheel drive vehicle, the differential on each axle can be dispensed with in this case, for example.
In typical applications, each electrical machine is controlled and supplied with electrical energy via a separate associated inverter. Such inverters are frequently implemented, for example, as standalone systems having an individual housing, wherein the electrical connection to the associated electrical machine is established using appropriate plug-in and/or bolted connections. The power electronics, including the inverter, requires a volume in this case that is not inconsiderable. Due to the fact that motor vehicles comprise a continuously increasing number of mechanical, hydraulic, and electrical components, it makes sense, however, to utilize the space inside the motor vehicle, which is naturally limited, in an optimal way. In order to make it possible to simultaneously minimize the energy requirement, the weight of the motor vehicle must also be kept as low as possible.
In order to more efficiently utilize the installation space in motor vehicles comprising multiple asynchronous machines, there is a need, therefore, for an improved concept for controlling the asynchronous machines.